supposing, of course, that there is good reason that this saying shines as first through all the others.
The elucidation of this prioritized first word demands special care. First of all, the characteristics of the foundational word τὸ δῦνον should be clarified. The word is a participle.  Th oughtlessly, we use the word τὸ δῦνον to mean “the submerging thing,” thinking the word in accordance with its nominal meaning. Indeed, our previous consideration, which in its essential features contained the elucidation of the guiding question of metaphysical thinking, revealed this: namely, that the thinkers understand τὸ ὄν (beings) in accordance with the way in which they think the being of beings, in the sense that they question beings on the basis of being. Being itself is unquestioned and taken for granted, for it is only in the light of being that beings can be asked about, and the question concerning what beings are can be answered.
However, the light itself remains unnoticed, just as one takes the day for granted and in its ‘light’ concerns oneself with the matters of the day. ‘Everydayness’ is a peculiar case;8 one lives, as one says, ‘one day at a time.’ Metaphysics from Plato through Nietzsche, which questions beings within the light of being, lives ‘one day at a time.’ One must, however, also know that in the ‘question concerning being’ so understood, for which being itself remains what is foremost unquestionable and before all else unquestioned, it is not only the case that being remains unquestioned, but also that metaphysics as metaphysics can never even ask the question concerning being itself. At the moment when the question ‘What is metaphysics?’ is asked, it is already asked from out of an entirely different sphere of inquiry. As a result, the question ‘What is metaphysics?’ is taken as a genuine question, and not only as the form by which the perpetually unquestioned metaphysics expresses its shape, structure, schemata, and disciplines. The chatter circulating today regarding the ‘question concerning being’ is the sign of a boundless bewilderment. This organized confusion of thinking was once even called ‘the revival of metaphysics.’
However, the current and dominant confusion of all concepts and ways of posing questions does not arise from a mere  shallowness of thinking: rather, the reason for the confusion conceals itself in an estrangement from being. When Nietzsche says that being is the last vapor of an evaporating reality, then he only pronounces, in his language and with the boldness of a metaphysical thinker, the final consequence of the truth that all metaphysics as such holds: namely, that being is the emptiest and most abstract concept, ‘the most general.’ It is still more honest to pass off being, taken as this conjectural abstraction of all abstractions, as a mere vapor, than it is to pretend that one is even asking ‘the question concerning being’ from within the estrangement from being.
8 See Being and Time (GA 2).
74 The Inception of Occidental Thinking